An Analysis of Competition among Autonomous Devices in Multichannel Cognitive Radios Networks

Executive Summary

The authors investigate an autonomous Opportunistic Spectrum Access (OSA) strategy for a multichannel Cognitive Radio (CR) network, where two or more autonomous CRs sense the channels sequentially in some sensing order to find a free channel to transmit on, if one exists. They evaluate the performance of the OSA strategy in terms of probability of success (probability that a given CR finds a channel free), mean time of success and throughput achievable by a CR. Surprisingly, they find that, when the number of potentially available channels is not large as compared to the number of CRs in the network, then having more free channels beyond a certain number actually hurts the CRs.